Search for catalytic properties of simple polypeptides

Area of Science:

• Origin of life studies
• Prebiotic chemistry
• Biopolymers

Background:

• Investigating the role of simple organic molecules in the origin of life.
• Understanding potential mechanisms for early genetic material formation.
• Exploring the catalytic and structural properties of polypeptides.

Purpose of the Study:

• To evaluate simple polypeptides as potential supports for template-free nucleotide polymerization.
• To determine the influence of specific polypeptide sequences on nucleotide linkage formation.
• To assess the catalytic activity of polypeptides in polymerization and hydrolysis reactions.

Main Methods:

• Synthesis and characterization of sequential polypeptide copolymers (alanine-glycine, arginine-based, poly(Glu-Ser-Glu)).
• Incubation of polypeptides with nucleotides under various conditions to study polymerization.
• Analysis of nucleotide linkage types (e.g., 2'-5' vs. 3'-5') formed.
• Investigation of polypeptide-mediated hydrolysis of oligoadenylic acids.

Main Results:

• No catalytic effect observed for alanine-glycine or arginine-based polypeptides in template-free nucleotide polymerization.
• Poly(Glu-Ser-Glu) demonstrated a preference for forming 2'-5' internucleotide linkages.
• Polypeptides containing arginine residues significantly accelerated the hydrolysis of oligoadenylic acids.
• Factors such as pH, temperature, buffer composition, and polypeptide sequence influenced hydrolysis rates.

Conclusions:

• Simple polypeptides may not have served as direct supports for template-free nucleotide polymerization in early Earth conditions.
• Arginine-rich polypeptides exhibit hydrolytic activity, suggesting a potential role in regulating early nucleic acid stability.
• The observed preference for 2'-5' linkages by poly(Glu-Ser-Glu) offers insights into potential non-enzymatic RNA formation pathways.